Liposomal restructuring induced by hemolytic Listeria monocytogenes was investigated by using flow cytometry. When added to calcein-entrapped liposomes, hemolytic, but not non-hemolytic, Listeria monocytogenes were able to induce reformation of vesicles. Such restructuring of liposomes was easily monitored by flow cytometry. Electron microscopy also indicated major changes in the challenged liposomal structures. The preliminary results described may offer a simple and fast method for monitoring liposomal restructuring and for differentiating between hemolytic and non-hemolytic bacteria.